Final answer:
A molecule formed in the midst of a metabolic pathway is called a metabolic intermediate. Metabolic pathways include anabolic and catabolic pathways, which are facilitated by enzymes to build up or break down molecules, thus defining an organism's metabolism.
Step-by-step explanation:
A molecule formed before a metabolic pathway reaches completion is called a metabolic intermediate. As part of metabolic pathways, these intermediates are crucial for the transformation of substrates into end products. Metabolic pathways are comprised of a series of biochemical reactions wherein substrates are converted, step-by-step, through various intermediates, ultimately leading to the final product.
There are two types of metabolic pathways: anabolic pathways, which require energy to synthesize larger molecules from smaller ones, and catabolic pathways, which release energy by breaking down larger molecules into smaller ones. Enzymes play a critical role in these pathways by catalyzing each step of the reaction. Because of these processes, metabolism is a balance of anabolism (building) and catabolism (degradation).